1. Field of the Invention
This specification relates to a refrigerator and a method for driving the same, and particularly, to a refrigerator having a refrigeration cycle with a plurality of compressors and evaporators, and a method for driving the same.
2. Background of the Invention
In general, a refrigerator is an apparatus for keeping an inside of the refrigerator at low temperature using a refrigeration cycle having a compressor, a condenser, an expansion apparatus and an evaporator. The compressor of the refrigerator is lubricated using oil for protection from a mechanical friction, and the oil within the compressor is allowed to circulate a refrigeration cycle forming a closed loop together with high temperature and high pressure refrigerant gas discharged out of the compressor.
If such oil is aggregated (accumulated) in the condenser, the evaporator and pipes of the refrigeration cycle, the performance of the refrigeration cycle may be lowered. If the oil does not smoothly flow back into the compressor, the lack of oil within the compressor may be caused, resulting in a damage of the compressor.
The refrigeration cycle applied to the refrigerator may be classified, according to the number of compressors and evaporators, into an 1Eva-cycle having a single compressor and a single evaporator, a parallel 2Eva cycle in which a plurality of evaporators are connected in parallel to an inlet of a single compressor, a 1Comp 2Stage cycle in which a plurality of evaporators are connected to a single 2-stage compressor, a serial cycle in which a plurality of evaporators are connected to the single compressor in series, a bypass serial cycle in which a plurality of evaporators are selectively connected to a single compressor in series.